Modeling the Growth of Listeria monocytogenes in Cured Ready-to-Eat Processed Meat Products by Manipulation of Sodium Chloride, Sodium Diacetate, Potassium Lactate, and Product Moisture Content

Abstract

A central composite second-order response surface design was employed to determine the influences of added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) on the predicted growth rate of Listeria monocytogenes in cured ready-to-eat (RTE) meat products. Increased amounts of both sodium diacetate (P < 0.11) and potassium lactate (P < 0.001) resulted in significant reductions in the growth rate constants of L monocytogenes. Increased finished-product moisture (P < 0.11) significantly increased growth rate constants. The nfluence of sodium chloride was not statistically significant. The second-order statistical factor for lactate was significant (P < 0.01), but all two-way interactions were not. In general, predicted growth rates exceeded actual growth rates obtained from inoculation studies of four cured RTE meat products (wieners, smoked-cooked ham, light bologna, and cotto salami). The final model will be useful to food technologists in determining formulations that will result in finished cured RTE meat products in which L. monocytogenes is not likely to grow.

Microbiological Spoilage of Meat and Poultry Products

“…All of these components may influence the potential spoilage and shelf life of the products. For example, combinations of potassium lactate and sodium diacetate, used to inhibit growth of the pathogen Listeria monocytogenes in these products, can also inhibit growth of spoilage microorganisms (Seman, Borger, Meyer, Hall, & Milkowski, 2002). Glass et al, (2002) and Seman et al (2002) determined that the lactate and diacetate combination is more effective in cured meat products than in uncured products.…”

“…For example, combinations of potassium lactate and sodium diacetate, used to inhibit growth of the pathogen Listeria monocytogenes in these products, can also inhibit growth of spoilage microorganisms (Seman, Borger, Meyer, Hall, & Milkowski, 2002). Glass et al, (2002) and Seman et al (2002) determined that the lactate and diacetate combination is more effective in cured meat products than in uncured products. Because of the nature of these uncured products, they will eventually be spoiled by a wide variety of microorganisms, including pseudomonads, lactic acid bacteria, enterococci, psychrotrophic Gram-negative bacteria, yeasts, and molds.…”

“…The spoilage of cured meat-packaged aerobically is caused, in most instances, by the growth of yeasts and molds. When the same cured products are packaged anaerobically in impermeable films, spoilage is caused by the growth of lactic acid bacteria, which include Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, Pediococcus, and Weissella (Seman et al, 2002). Microorganisms from the genus Brochothrix are also responsible for spoilage in cured meat.…”

Nitrates and Nitrites in meat products

“…Nitrites with sodium lactate and sodium diacetate have been found to act synergistically against Listeria monocytogenes in cured meat products (Seman et al, 2002;Gill and Holley, 2003;Legan et al, 2004;USDA, 2006). Milkowski et al (2010) reported inhibitory activity of nitrites against L. monocytogenes, E. coli O157:H7, S. aureus, and Bacillus cereus in cured meat products.…”

Modelling the growth rate ofListeria monocytogenesin cooked ham stored at different temperatures

“…Different growth rates might be obtained by testing in other environments and with L. monocytogenes from other sources (31). However, the cured, cooked ham used in this study met the requirements laid down in the Polish standard (26) and its manufacturing and chemical composition was typical for this kind of product.…”